The sequel to the hugely popular Half-Life computer game is due for release this year.

Games gossip sites on the net have been set buzzing this weekend by the announcement that Half-Life 2 will be on show at the forthcoming E3 trade fair.

Half-Life maker Valve Software has also said that the finished version of the game should be on sale by the end of 2003.

The release of the game has been eagerly anticipated by gamers who have become big fans of the original.

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Half-Life has been a firm favourite among computer gamers ever since it first appeared in late 1998.

At the time of its release Half-Life won praise for its strong plotting, intricate puzzles, atmosphere and the intelligence of the in-game enemies that players had to take on.

Half-Life could face competition from Doom III

The game put players in the shoes of hapless laboratory assistant Gordon Freeman, who, thanks to a catastrophic accident, gets the job of saving the world from legions of inter-dimensional beasties.

Interest in the game has been maintained over the last few years by regular updates, such as Opposing Force and Blue Shift, which gave players the chance to take on the role of other people forced to deal with the invasion of monsters.

Half-Life also spawned Counter-Strike which is now the net's most popular multi-player game.

Despite being years old Half-Life regularly tops reader polls in games magazines that chart players' favourite titles.

So far details of the eagerly anticipated Half-Life 2 are scant but Valve has said that games magazines can write about the game from 28 April.

It is not yet known whether the new Half-Life follows the original and remains a first-person shooter.

Add-ons for Half-Life have kept it popular

Some changes look likely if the cover of Belgian games magazine PC Gameplay is any guide. The cover shows a screenshot from the game in which hero Gordon Freeman is seen standing next to a woman in a wintry landscape.

Valve is planning to show much more at the Electronics Entertainment Expo to be held in Los Angeles from the 13-16 May.

Despite being eagerly, awaited the new Half-Life will face much stiffer competition than its first incarnation because so many games have built on and improved the game-play techniques that the original pioneered

If nothing else Half-Life 2 will face a threat from Doom III, another eagerly anticipated title that is due for release soon.

Some suspect that, despite Valve's claims, the development of the game will slip and it will not be released this year.